Tire sizes - 275/60r15 rear - fronts 235/70r15 OR 255/60r15???

[Chuck78]

I am torn between tire selection coices looking for some input. I use my truck for hauling medium loads and once in a great while, pulling a trailer. Load ratings are critical for me, but so is a good handling tire. Shorter tread life expectancy is a bonus for me as that means better road grip.

I got a set of four 5 lug 5" b.c. American Racing Torque Thrust 15x8's with 275/60r15 Firestone Firehawk Indy 500's on them - I will use the 275/60r15's only on the rear.

I'm very pleased with the look, load capacity (2174lbs?), and road grip of the rears on my redrilled Dana 44 axles. On the front, I have some late 70's Blazer (so I am told) aluminum 15x7 6 lug wheels for now until I swap the 73-91 Suburban disc brake front end.


NOW...
On the fronts, I'm looking at either a 235/70r15 OR a 255/60r15.
I have ooollldddddddd G60-15's on it now, basically a 245/60-15. They have a great width, but the 25" diameter looks slightly too small in the big fenderwells. I had to lower the torsion bar suspension ride height to make them look somewhat acceptable.


Pros/Cons:

235/70r15
*1,929lbs load rating - slightly higher than the 255/60 - this panel truck has a monstrously heavy 800 lb GMC big block v6.
*fills up the fenderwell better, 28" height matches the 28.1" of the rear
*28" height will give slightly better ground clearance by 1/2" - heavy engine may need extra suspension travel
*narrower - will get more bite per square inch on wet roads, more sidewall squirm/flex in corners however
*narrower - if I keep the manual steering, 235 will be slightly more manageable parallel parking etc.
*narrower - these may not look as good on a 15x8 rim when I swap to the 5 lug disc brake front end. They are an acceptable fit on an 8" rim however, per manufacturer.


255/60r15
*1,874lbs load rating - less than the 235/70 but not by much - 54lbs less per ft tire
**255 wider width will definitely make it handle better on windy roads and turns. I do greatly enjoy a sporty ride, getting better handling in curves on my light hauler truck would be a bonus
**27.1" overall height makes the 60 series sidewall 1/2" shorter than the 235/70 - this tire will definitely squirm less in the turns, giving it better handling. With a monster 800 lb GMC big block v6 engine, the squirm may be even more than average - the 255/60 will be a big plus for the sporty ride factor
*?*will a 27.1" height still look too small in this big 60-66 front fenderwell??? The 26" 245/60-15 looks too small for a truck. 28" looks great
*255 width will get better grip on dry pavement but slightly less on wet pavement. Will the extra grippy Maxxis tread compound, massive weight of the GMC big block v6, & the Vee type directional tread pattern make up for the extra width in terms of wet pavement traction?
*255 width will look more squared off and proper when mounted on the 15x8 5 lug wheels that I plan to swap when I do the 1989 Suburban 5 lug disc brake crossmember swap.


Photos later, I have to air up the dry rotted front tires when I get home.